This service area includes those items used to create, edit, compose, or present data on any combination of media. In this context, the term "data" refers to all types of information used within the DODIIS community (see section 3.1 ), and a medium is the means by which data is perceived, expressed, stored, or transmitted. Table 2-6 summarizes the DODIIS standards adopted for the multimedia services.
This component provides the interfaces for programming two- and three-dimensional graphics in a device-independent manner. Within the DODIIS community it is envisioned that two dimensional graphics will meet the majority of the graphical display needs for support of map graphics and facility plans. Three-dimensional capability will be useful for applications requiring either terrain or equipment visualization.
Whereas the Graphical Kernel System (GKS) has previously been the standard of choice for two- dimensional graphics, the library of functions which are part of the X Window System, described in section 2.2.1, provides similar functionality without the penalty of increased application cost, execution overhead, and portability. Similarly, the Programmer's Hierarchical Interactive Graphics System (PHIGS), a hierarchical, interactive system to define, modify, and display two and three-dimensional data, was previously the de facto standard for three-dimensional graphics. PHIGS provides advanced concepts in a graphics standard such as structures, structure editing, traversal-time attribute binding of attributes, and control over detectability, highlighting, and visibility of output primitives. However, PHIGS is being replaced within the X Window client server environments by the PHIGS Extension to X (PEX).
PEX allows each window on a workstation screen to act as a complete, independent, virtual three- dimensional graphics workstation. PEX 5.0 and 5.1 were released with X11R5. Although PEX is adopted as a gap standard, DODIIS applications that need additional capabilities and interfaces for programming three-dimensional graphics are encouraged to use higher level libraries as available.
The imagery services provide support for the manipulation of image data. Within DODIIS, this support will be based on routines provided by X Image Extensions (XIE) and the Programmers Imaging Kernel System (PIKS) portion of the Image Processing and Interchange (IPI) standard (ISO/IEC 12087). Currently under development by the ISO, IPI is an outgrowth of the Programmers Imaging Kernel (PIK) standard.
XIE, part of X11R6, provides for image processing in the X server, enhancing X in terms of image transmission, display and manipulation. XIE is typically used for such things as the storage of scanned documents on the server side. As with PEX, XIE is being adopted as a gap filler at this time, but developers are encouraged to use highest level library available.
The goals of XIE stop short of defining a full image processing standard, leaving such functionality to other standards on the client side, such as IPI PIKS. PIKS provides a toolkit of image processing API elements to simplify and unify imaging application development. Analogous to the X Window API, PIKS is a toolkit of functionality which standardizes the interaction of applications with image processing hardware and underlying operating systems. While image processing applications are often hardware dependent or make use of direct operating system calls, PIKS will abstract image processing functionality from specific hardware or operating system software to achieve hardware independence and portability of applications.
Another part of the IPI standard which is specified by the PIKS is the Common Architecture for Imaging (CAI). The CAI provides a generic architectural umbrella for image processing and the interchange of image data. Common acceptance of CAI will allow implementors to begin developing application modules which can interact with PIKS or other imaging elements. It also provides the groundwork for future imaging API and interchange standards as technology develops.
Security services included in this area concern access to and the integrity of functions that support the development of data, such as graphics, and imagery.
Standards for security in this area (e.g., graphics, video) have not been formally defined at this time. As the security standards or related activities mature, they will be included in a future version of the DODIIS Profile.